TRIM /TILT QUESTIOIN

[SHickey]

Hello,
After using my 1976 Starcraft 20' American (165 HP & MC-1 O/D) all over Keuya Lake for vacation I noticed my outdrive was failing to go up all the way if I was in shallow water. Going down was fine but going up, I needed to hit the down button and up button rapidly until I could hear the oil pumping but still the unit only partially went up.

At the dock I added a little bit of oil to the reservoir and it did work better going up 1/2 way but still not all the way up. Not sure what to do at this point, I see no obvious leaks around the pump or the hoses and it seems to go up to the 1/2 way point and nothing more.

Any suggestions or tips for getting the trim/tilt unit working properly??

 

[s.hadley81]

If your using the trim button it shouldn't go all the way up. It should only go all the way up for trailering. Running with the drive up too much can hurt the u joints. There are trim limits that keep the drive from going up too much they will stop the drive from going up too much to avoid damage. Do you have a button marked trailer ? Also a pic of the controls could help.

 

[SHickey]

Thanks for the response!!

It is my understanding that the previous owner bypassed the limit switch and since the time I have had the boat the tilt/trim has worked fine up until now. I am not good with posting pictures but the trim/ tilt has ( on the dash board) a black toggle switch for up and down and a red toggle for trailering mode. The black toggle only works for down and does nothing in the up position. To raise the LU the red toggle is pushed down and the LU goes up depending on how long it is held down.
There is no "automatic" stopping of the trim / tilt when it is activated in the down or up positions.

I am thinking that maybe something internally in the pump or reservoir is leaking or loosing pressure when the pump is trying to pressurize the rams to raise the OD. Any thoughts or similar experiences with this kind of problem??

 

[tpenfield]

You may need to add more fluid. Otherwise the issue could be with the check valves within the pump, or possibly the ram cylinders.

Try the additional fluid first and see if it makes a further improvement,

 

[SHickey]

Thanks for the response!

The fluid is right up to level so maybe the check valves in the pump may be leaking or the rams are not extending to their fullest length. What would be the best way or test to figure out what the problem is and how difficult is the pump to take apart and replace the valves?

Thanks again.

 

[SHickey]

Hello again

I was working on my boat this weekend and I discovered one of the fluid lines was leaking at the bottom of the reservoir. I tighten it up and topped off the reservoir and the O/D goes up a little better but still not all the way up for trailering

I also discovered it creeps down after it sit awhile in the up position. I was wondering what I should look at to get the unit working properly. I can remove the trim/tilt unit this fall and the rams if necessary. I don't mind taking the pump apart but I hear that resealing the rams is a difficult job,

 

[Bondo]

I also discovered it creeps down after it sit awhile in the up position.

Ayuh,...... At the base of the rams, unhook the short hose from the ram, remove the other hose from the manifold, 'n put the other end of the short hose back to the manifold,....
Run it Up, 'n leave it,....
If it drops again, reconnect that ram, do the same operation on the other ram, run it Up, 'n leave it alone again,....

If it falls again, the problem is in the pump's valves,....

 

[SHickey]

Thanks for the response

My rams have two hoses each going to the manifold and they both appear to have the same length. If I number the port ram 1&2 and the starboard ram 3&4, can you tell me which hoses to connect to at the manifold for the test.

Sorry for my confusion

 

[Bondo]

Ayuh,..... Disconnect one hose from the manifold, 'n the other from the ram,....

Then attach the one still hooked to the manifold, back to the manifold,....

It don't matter which one, yer just by-passin' the ram,...

 

[SHickey]

Hello,

I tried the hose test and the O/D failed to go up at all. I could manually raise and lower the O/D with my hand. I assumed it would not raise due to the lower oil level in the reservoir since I lost some oil for the test. I returned the hoses back to their original locations and topped off the reservoir. Now the pump is running but the unit does not seem to be priming or pumping. Now the pump is not making the usual sound when the unit did go up or down, it sounds like it is not pressurizing the oil.

So now my unit does not go up or down and it has a reservoir full of oil. I guess I won't be taking my boat out anytime soon. Any suggestions what my next step should be to rectify this situation would be appreciated and thanks in advance.

 

[SHickey]

Hello again,

Since my trim pump no longer raises or lowers my unit, I was thinking of draining the oil and replacing it with fresh oil if anyone thinks it could solve my situation. Another option I have is to swap out a 1976 Mercruiser 140 trim motor for the 1976 Mercruiser 165 trim motor which is not operating properly. The trim motor on the 140 works fine but I am not sure if they can be interchanged.

Either way it's a messy job working on these trim motors when you have to remove the hoses

Any comment would be most appreciated!!

 

[Bondo]

Another option I have is to swap out a 1976 Mercruiser 140 trim motor for the 1976 Mercruiser 165 trim motor which is not operating properly. The trim motor on the 140 works fine but I am not sure if they can be interchanged.

Either way it's a messy job working on these trim motors when you have to remove the hoses

Ayuh,..... Same pumps, swap 'em out,....

Havin' the drive fully down sometimes helps with the oil mess,.... No pressure on nothin',....

Lotsa cotton rags are an important tool too,....

 

[SHickey]

Thanks for the response.

I am glad to hear the pumps are interchangeable.

I did buy a $21 quart of Quicksilver trim fluid and I was thinking about draining the reservoir holding the old questionable fluid with some 30 w oil (added to it over the last season) and replacing the fluid with the recommended fluid before I swap out the trim motors.

Does anyone think that would be worth trying or should I save the Quicksilver fluid for the operating trim motor off of the 140??

Thanks again for the responses

 

[KJM]

save the good oil for the new pump, the oil is not the problem. I just use regular 5w20 motor oil in mine with no problems. I had my pump apart last year and repaired a brush in the electric motor. the actual pump looked pretty simple and i'm sure wouldn't be hard to fix. and like bondo said, get lots of rags handy!

 

[SHickey]

Thanks for the response.

I looked up Trim motor parts on a Mercruiser parts website and a new pump runs @ $700 and the valve assembly runs @ $250 if my memory serves me. Some part sites list the valve assembly as "no longer available".

Since my two pumps are the same I was hoping to refurbish the failed one but the cost seem to be a little prohibitive.

Maybe my best bet is to contact my used parts buddy in Newark, NY and see if he has any old usable pumps available.

Any other suggestions would be most appreciated (you can tell I am stalling to complete this messy job):facepalm:

 

[SHickey]

Hello,
I pulled out the trim pump from my boat and it was one of the most difficult jobs I have ever tackled on this boat. The pump is mounted with 3 bolts, two are visible and the 3rd is hidden and not easy to take apart.

The bad pump I removed has 2 solenoids, the other pump I have to replace it with has only one. The trim pumps have the same part number and they look identical.

My question is : is there any cleaning or maintenance I should perform on the good pump before I switch the 2 solenoids to the good pump and install it in the boat??

Since these pumps are not easy to remove due to their location, I would like to prevent any future failure if I can since both pumps are sitting on my work bench.

Thanks again for any responses.

 

[SHickey]

Well,

I swapped the trim motor pumps and the trim / tilt couldn't work better. The unit goes so high that it shuts itself off.

What I am noticing now is the tilt gauge is slowly creeping up when the unit is at full down. After a few minutes the gauge shows the unit is 1/2 up even though the unit is full down. Any suggestions??

I am so happy the unit is operating but if I can get the gauge to display the current tilt angle, that would be even better!!

Thanks again for the responses.

 

[Pete104]

Sounds like you have the hydraulic sender with the limit switch stuffed up in gimbal housing. I'm shocked that the limit switch still functions as it should. I'm attaching a link to a source that most everyone here uses. http://boatinfo.no/lib/mercruiser/manuals/mercruiser2.html#/544
Sounds like you have enough patience to make great things happen to this old girl.
Now if you want more info on your set up go here http://boatinfo.no/lib/mercruiser/manuals/mercruiser2.html#/0 this is the complete manual for your engine.

As I said I'm really surprised that the limit switch still worked. Can't tell you how many of those I've replaced or just bypassed them. But the hydraulic sender, that should last forever or as long as the gauge is good. Sounds like it has a pulse atleast. Get it working and maybe Mercury will want to put in a museum.

If you can put some pics up.

Good luck

 

[SHickey]

Thanks for the response,

I do have a lot of patience for this old gal but not very much working knowledge of how these trim/tilt systems work except for the very basics. I do have a decent service manual for the 165 Mercruiser and MC-1 OD so I will look into it and see if there is a trouble shooting symptom for this fluctuating gauge issue that may be addressed in the manual.

Thanks again for the information.

 

[johnkom]

I have the same setup on my "76 Sea Ray. It sounds like you may have some air in the sending unit for the indicator. As you use it it should work its way out. Really not worth bleeding although there is a procedure for that in the manual. When my gauge got jumpy I cleaned the sliding rheostat on the end of the sender. Works like new again.

JK